Junction-box for electric circuits.



F. KRATZ.

JUNCTION BOX FOR ELECTRIC CIRCUITS.

APPLICATION FILED JUNE 5, I914.

Patented Apr. 25, 1916.

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' JUNCTION BOX FOR ELECTRIC CIRCUITS.

APPLICATION FILED JUNE 5,1914.

Apr. 25, 1916.

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UNITED STATES PATENT OFFICE.

FRANZ KRATZ, OF STUTTGART, GERMANY, ASSIGNOR TO THE FIRM 0F ROBERTBOSCH, OF STUTTGART, GERMANY.

JUNCTION-BOX FOR ELECTRIC CIRCUITS.

Specification of Letters Patent.

Patented Apr. 25, 1916.

To all whom it may concern Be it known that I, FRANZ Knx'rz, a subjectof the Emperor of Germany, residin at and whose post-office address isSchlosstrasse 59 Stuttgart, Germany, have invented certain new anduseful Improvements in Junction-Boxes for Electric Circuits; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same.

The object of the present invention is to provide a fused junction boxparticularly suitable for electrically connecting two supply conductorsto two distributing conductors which, preferably, are in the form of aconcentric-conductor cable in which the metal armor of the cable mayform one conductor. In using a junction box of this kind with a storagebattery, all parts of the junction box including the joints areprotected from fumes of the battery, the lead covered connecting wiresextending from the battery terminals through the battery box, which isusually of wood, and into the junction box mounted on the outsidethereof. The junction box of my invention is simple and compact andembodies a fuse receptacle which may be easily removed for renewal ofthe fuse and also a connecting arrangement such that the distributingcable may be readily connected and disconnected, all the parts being sosecurely fastened in place that the continual vibration occurring whenthe equipment is installed on a moving vehicle does not loosen theconnections even after a long period of use.

In the accompanying drawings, illustrat ing' the preferred form of myinvention in application to a storage battery having acontaining box ofwood, as an example, Figure 1 shows a section on line 11 of Fig. 3; Fig.2 shows a section on line 22 of Fig. 1; Fig. 3 represents a front viewof the junction box; Fig. 4 is a section on line i+l of Fig. 2, omittingthe distributing cable; and Fig. 5 is a section on line 55 of 2.

The metal housing a of the junction box is closed on one face, and isopen on the opposite face which rests against the fiat surface of thecontaining box to for the storage battery. The junction box has adiametrically-disposed metal partition I) and is also provided with ascrew-threaded socket c on one side of the partition and a flangedopening (Z on the other side. An abutment member f of metal. is insertedthrough an opening in the partition 7) and. is insulated there from asshown. This abutment member has opposed conical contact surfaces. Acrescent shaped terminal member 9 of metal is fastened to the housing bythe screws 2' and 2', which are insulated from the member as shown, andthe terminal member is further insulated from the housing by means ofthe insulating sleeve 6 passing through the hole (Z in the housing. Thefuse receptacle 0 comprises a cylinder of glass inclosing a fuse ofsuitable material which is connected to the terminals of the fusereceptacle. The threaded plug m of metal engages the screw threads ofthe terminal member 0 to thereby connect the terminal member with oneterminal of the fuse receptacle and to maintain the other terminal ofthe fuse receptacle in contact with the conical surface of the abutmentmember f. The threaded plug a of metal is slipped over the end of adistributing cable having the inner conductor 7' and the conductingsheathing s. The terminal shoe 7) is connected to the armor of thecable, but is insulated from the tip 2? which is con.- nected to theinner conductor 1'. By screwing the plug 7?, into place, the armor s ofthe distributing cable is electrically connected to the housing a of thejunction box, and at the same time the core 7' of theconcentric-conductor distributing cable is maintained in electricalcontact with the conical surface of the abutment member 7'. The leadcovered conductors 7: and Z1, extend from the terminals of the batteryand through the battery box 1 to the terminal member 5/ and thepartition Z) as shown. so that the terminals of the battery are thusconnected through the fuse receptacle 0 to the two conductors 'r' and sof the distributing cable. The junction box is fastened to the container10 by screws a passing through the partition I).

The current from the battery flows from the positive terminal throughthe lead covered conductor is into the terminal member 9 of the junctionbox, from which it passes through the plug m, fuse 0 and abutment memberf, into the conductor 1" of the distributing cable. The current returnsby way of the sheathing s of the distributing cable and the terminalshoe 29, through the plug a, metal housing a, partition I), andconductor 7a, to the negative battery terminal.

In installing the junction box on the battery box, the ends of theconductors in, is, are soldered in their receiving holes in the members9 and b, respectively, and then after the junction box is fastened tothe battery box by the screws 1;, the other ends of the conductors is,76 are soldered in the holes in the battery terminals.

The fuse receptacle 0 may be removed from the junction box by unscrewingthe plug m, and thus the fuse in the receptacle may be easily renewed;and likewise the distributing cable may be easily removed by unscrewingthe plug a. However,'the fuse receptacle and the distributing cable arenormally held securely in place, so that the two terminals of thebattery are reliably connected to the two conductors of the cable, insuch manner as to withstand severe vibration over an extended period ofoperation.

Having thus described my invention, what I claim is:

1. In a junction box having two terminals insulated from each other andalso having a partition, an abutment member extending through and beinginsulated from the partition and having opposed contact surfaces, a fusereceptacle, a plug connecting one terminal of the junction box to oneterminal of the fuse receptacle and maintaining the other terminal ofthe fuse receptacle in engagement with one contact surface of theabutment member, and a second plug designed to connect one distributingconductor to the other terminal of the junction box and to maintainanother distributing conductor in engagement with the other contactsurface of the abutment member.

2. In a junction box having a housing designed to be connected to onesupply conductor and also having a partition, a terminal memberinsulated from the housing of the junction box and designed to beconnected to another supply conductor, an abutment member extendingthrough and being insulated from the partition and having opposedcontact surfaces, a fuse receptacle passing through said terminalmember, a plug connecting the terminal member to one terminal of thefuse receptacle and maintaining the other terminal of the fusereceptacle in engagement with one contact surface of the abutmentmember, and a second plug designed to connect one distributing conductorto the housing of the junction box and another distributing conductor tothe other contact surface of the abutment member.

3. The conbination with a multiple conductor distributing cable, of ajunction box having two terminals insulated from each other, aninsulated abutment member, a fuse receptacle, a plug connecting oneterminal of the junction box to one terminal of the fuse receptacle andmaintaining the other terminal of the fuse receptacle in contact withthe abutment member, and a second plug connecting one conductor of thecable to the other terminal of the junction box and maintaining anotherconductor of the cable in contact with the abutment member.

4. The combination with a concentricconductor distributing cable, of ajunction box having two terminals insulated from each other, aninsulated abutment member, a fuse receptacle, a plug connecting oneterminal of the junction box to one terminal of the fuse receptacle andmaintaining the other terminal of the fuse receptacle in contact withthe abutment member, and a hollow plug surrounding the cable andconnecting one conductor thereof to the housing and holding anotherconductor thereof in contact with the abutment member.

5. The combination with a concentricconductor cable, of a junction boxhaving two terminals insulated from each other, an insulated abutmentmember of metal having opposed conical contact surfaces, a fusereceptacle, a plug connecting one terminal of the junction box to oneterminal of the fuse Copies of this patent may be obtained for fivecents each, by addressing the Commissioner 01. Patents, Washington, D.O.

